Thank you Bryan,
I ended up using the following code, but I like your ifelse example better

DOL1 <- which( DOL==0.0050 )
DOL2 <- which( DOL==0.0100 )
DOL3 <- which( DOL==0.0150 )
DOL4 <- which( DOL==0.0200 )
DOL5 <- which( DOL==0.0250 )
DOL6 <- which( DOL==0.0300 )

ShotData[DOL1,”DOL.lvl”] <- 0;
ShotData[DOL2,”DOL.lvl”] <- 0;
ShotData[DOL3,”DOL.lvl”] <- .5;
ShotData[DOL4,”DOL.lvl”] <- .5;
ShotData[DOL5,”DOL.lvl”] <- 1;
ShotData[DOL6,”DOL.lvl”] <- 1;